StasyukS. A. (2002). Best $M$-Term Trigonometric Approximations of the Classes $B_{p,θ}^Ω$ of Functions of Many Variables. Ukrains’kyi Matematychnyi Zhurnal, 54(3), 381-394. Retrieved from https://umj.imath.kiev.ua/index.php/umj/article/view/4074